Cylinder heads for internal combustion engines



Dec. 7, 1965 A. WILLIAMSON 3,221,723

CYLINDER HEADS FOR INTERNAL COMBUSTION ENGINES Filed Feb. 26, 1964 s SheetS -Sheet 1 CYLINDER HEADS FOR INTERNAL COMBUSTION ENGINES Filed Feb. 26, 1964 Dc. 7, 1965 A. WILLIAMSON 5 Sheets-Sheet 2 1965 A. WILLIAMSON 3,22 ,7 3

CYLINDER HEADS FOR INTERNAL COMBUSTION ENGINES Filed Feb. 26, 1964 5 Sheets-Sheet 5 U f WQ 1 n 0 en to r fldemmer KHz/K 3 075022 United States Patent 3,221,723 CYLINDER HEADS FUR INTERNAL COMBUSTION ENGINES Alexander Williamson, Luton, England, assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Filed Feb. 26, 1964, Ser. No. 347,559 Claims priority, application Great Britain, Feb. 27, 1963, 7,797/ 63 7 Claims. (Cl. 12341.77)

This invention relates to internal combustion engine cylinder heads.

An internal combustion engine cylinder head according to the invention is formed as a casting which is in two parts, the head being divided in a plane parallel or at an angle to the upper and lower faces of the cylinder head at a distance between said faces such that the exhaust passages lie wholly within one part of the casting and a substantial portion of the inlet passages lies in the same portion of the casting, the inlet manifold, and the other portion of the inlet passages lying wholly within the other part of the casting, the portions of the inlet passages lying within the respective parts of the casting having joint faces the periphery of which is not substantially greater than that of the cross-section of the inlet passage.

The inlet and exhaust passages taper towards their junction with a combustion chamber recess in the lower face of the cylinder head and the configuration of the combustion chamber at its junction with the inner end of the inlet and exhaust passages is such that there is a slight taper towards such junction; and the inlet manifold passage tapers from each end of the upper part of the casting towards the transverse central plane thereof.

The passages for the circulation of liquid coolant in the cylinder head are formed by recesses in the lower part of the casting, the upper peripheral portions of such recesses being closed by the lower plane face on the upper part of the casting which may have complementary recesses therein, when the two parts are secured together with a sealing medium therebetween; and the passages are interconnected by a rectilinear passage which tapers from either end of the cylinder head towards the transverse centre plane thereof.

The scope of the invention is defined by the appended claims; and the invention and the method by which it is to be performed are hereinafter particularly described with reference to the accompanying drawings in which:

FIGURE 1 is a composite plan of an internal combustion engine cylinder head according to the invention, the left-hand half of the figure being a plan of the top half of the cylinder head and the right-hand half of the figure being a plan of the bottom half of the cylinder head;

FIGURE 2 is a section on the line 2-2 of FIGURE 1;

FIGURE 3 is a section on the line 3-3 of FIGURE 1;

FIGURE 4 is a composite sectional view, the left-hand half of the figure being a section on the line 44 of FIG- URE 2 and the right-hand half of the figure being a section on the line 55 of FIGURE 2.

The cylinder head shown in the drawings is formed as two castings comprising an upper part 1 and a lower part 2, the two parts of the cylinder head, when assembled on the engine being secured together and to the engine block by means of bolts (not shown) which pass through aligned openings 3 and 4 respectively in the upper and lower parts, a gasket or a sealing compound (not shown) being interposed between the two parts 1, 2.

As shown in particular in FIGURES 2 and 3 the cylinder head is divided, to form the two parts 1, 2 in a plane parallel to the upper and lower faces of the cylinder head and at a distance between the upper and lower faces such that exhaust passages 5 (FIGURE 3) lie wholly within the lower part 2 of the cylinder head and a substantial 3,221,723 Patented Dec. 7, 1965 portion of inlet passages 6 (FIGURE 2) lies in the same portion 2 of the cylinder head.

The exhaust passages 5 taper from an outer face 7 in a direction towards the combustion chambers 8 with which they are in communication, the inner end of each exhaust passage 5 being at an angle to the major portion of the exhaust passage and being formed as a short passage 10 which extends upwardly from the combustion chamber 8 and tapers towards its junction with the major portion of the exhaust passage 5.

The lower cylinder head portion 2 is formed with bores 11 for the mounting of exhaust valves (not shown), each bore 11 communicating with the inner portion 10 of an exhaust passage 5. Similarly, further bores 12, to receive inlet valves (not shown) are formed in the lower cylinder head portion 2 and respectively communicate with the inner ends 14 of the inlet passages 6, the latter being each formed as a short passage which extends upwardly from the combustion chamber 8 and tapers towards its junction with the portion of the inlet passage 6 which lies in the lower cylinder head portion 2. The inlet passages 6 each taper from their junctions with an intake manifold 15 towards their junctions with the inner end portions 14 of the inlet passages. As shown in FIGURE 4, the inlet manifold tapers from each end thereof towards a point half Way therealong at which it is in communication with a carburetor connector seat 16.

The lower part 2 of the cylinder head is cast with a water cooling passage 17 which extends from one end to the other of the cylinder head and, as shown in FIG- URE 3, extends around the exhaust passages 5 and the combustion chamber 8. The passage 17 is in communication with a further rectilinear passage 18 which extends from one end to the other of the cylinder head part 2 and tapers from each end of the lower part of the cylinder head to the central transverse plane thereof, as shown in FIGURE 4.

The lower part 2 of the cylinder head is also formed with a cavity 29 therein at the bottom of which is a bore 21 through which a push rod for valve actuator mechanisms (not shown) is adapted to extend.

The upper part 1 of the cylinder head has therein the outer end of each inlet passage 6, 14 which opens into the inlet manifold 15.

Cavities 22 in the upper cylinder head portion 1 are interconnected by longitudinal passages 23 which are formed as parts of a tubular passage which extends longitudinally of the cylinder head and tapers from each end towards the transverse central plane thereof, the cavities 22 overlying the portions of the passages 17 extending above the exhaust passages 5 and forming therewith, and with the passages 18 and 23 a passage system for the flow of a coolant liquid from one end to the other of the cylinder head.

As shown in FIGURES l and 4 the coolant circulation passages 22, 23 are in communication at one end of the upper part 1 of the cylinder head with a manifold 24 having thereon a plane seat 25 to which a connector member from the radiator of the engine may be connected.

The upper part 1 of the cylinder head is formed with a plurality of upwardly extending pillars 26 in which are formed tapped openings 27 for the reception of correspondingly threaded portions of valve actuator mechanisms (not shown). The base of the upper part 1 is also formed with openings 28, 29 therein which respectively overlie the valve stem openings 11, 12 in the lower part 2 of the cylinder head.

With the above described construction and configuration of the cylinder head the two parts 1, 2 thereof may be readily formed as pressure die castings, for example in a light metal alloy, the construction enabling the light alloy casting to be made as a die casting with the employment of metal split dies and metal cores, the employment of any sand cores being eliminated; these tapered metal cores are employed to form the recesses for the coolant passages 17, 18, the combustion chamber recesses 8, l and 8, 14 and the inlet passages 6 in the lower half 2 of the cylinder head casting and also to form the exhaust passages 5 therein and the cavities 20. In the upper portion 1 of the casting the inlet manifold 15 and the adjoining portions of the inlet passages 6 are also formed by the employment of tapered metal cores, as are the recesses 22 and the passages 23, and the recessed portions in the upper part 1 of the head which extend about the pillars 26. The manifold 15, the passage 18 and the passages 23 are respectively formed by pairs of tapered metal cores which extend from each end of the head towards the central transverse plane thereof, these cores being inserted from either end of the die and being first removed from the die before the latter is opened at the conclusion of a casting operation.

A cylinder head constructed in accordance with the invention has the advantage that the possibility of leakage, particularly leakage between the liquid coolant passages 17, 22 and the combustion chambers 8 or exhaust passages 5 is thereby substantially reduced or eliminated in the event of the jointing between the two parts of the casting being imperfect; and as shown in the right hand half of FIGURE 1, the perimeter of the joint faces between parts of the casting which separate liquid coolant passages from exhaust or inlet passages is also reduced as compared with previous constructions, thereby also reducing the liability to leakage. In particular, the periphery of the joint face between the two parts of each inlet passage 6 is not substantially greater than that of the cross section of the passage.

The cylinder head construction in accordance with the invention also has the advantage that it enables the tolerance in the dimensions on the thickhess of the casting to be reduced from approximately .1875 inch to .16 inch thus permitting a greater degree of accuracy in the finished parts and reducing the finishing operations which are required on the casting after manufacture. The formation of all the gas and liquid passages with the employment of metal cores also results in a substantially improved flow through such passages as they have a relatively high degree of surface finish as compared with those which would be obtained with the employment of sand cores.

Although the cylinder head described above is divided into upper and lower faces so that the plane between the two parts is parallel to the upper and lower faces of the head, the plane between the two parts may if desired be an at angle to the upper and lower faces of the head.

I claim:

1. An internal combustion engine cylinder head having therein an inlet manifold, inlet and exhaust passages, and passages for the flow of liquid coolant therethrough and formed as a two-part casting, said head being divided, so as to form an upper and a lower cylinder head part, in a plane which intersects opposite sides of the head and is so spaced from the upper and lower faces of the cylinder head that said exhaust passages lie wholly within the 4 lower part of the casting and that a substantial portion of each of said inlet passages lies in said lower part of the casting; the inlet manifold and the other portion of said inlet passages lying wholly within the upper part of the casting.

2. An internal combustion engine cylinder head having therein an inlet manifold, inlet and exhaust passages and passages for the flow of liquid coolant therethrough and formed as a two-part casting, said head being divided, so as to form an upper and a lower cylinder head part, in a plane which intersects opposite sides of the head and is so spaced from the upper and lower faces of the cylinder ead that said exhaust passages lie wholly within one part of the casting and that a substantial portion of each of said inlet passages lies in the same part of the casting; the inlet manifold and the other portion of said inlet passages lying wholly within the other part of the casting.

3. An internal combustion engine cylinder head having therein an inlet manifold, inlet and exhaust passages, and passages for the flow of liquid coolant therethrough and formed as a two-part casting, said head being divided, so as to form an upper and a lower cylinder head part, in a plane which is parallel to and is so spaced from the upper and lower faces of the cylinder head that said exhaust passages lie wholly within the lower part of the casting and that a substantial portion of each of said inlet passages lies in said lower part of the casting; the inlet manifold and the other portion of said inlet passages lying wholly within the upper part of the casting.

4. An internal combustion engine cylinder head according to claim 1, in which an inlet passage and an adjacent exhaust passage each taper towards their junction with a combustion chamber recess in the lower face of the cylinder head and the configuration of the combustion chamber at its junction with the inner ends of the exhaust and inlet passages is such that there is a slight taper towards said junction.

5. An internal combustion engine cylinder head according to claim 4, in which said inlet manifold tapers from each end of the upper part of the casting towards the transverse central plane thereof.

6. An internal combustion engine cylinder head according to claim 1, in which said passages for the flow of liquid coolant are formed by recesses in the lower part of the casting, the upper peripheral portions of such recesses being closed by the lower plane face of the upper part of the casting when the two parts are secured together with a sealing medium therebetween.

7. An internal combustion engine cylinder head according to claim 6, in which the coolant flow passages are interconnected by a rectilinear passage which extends from either end of the cylinder head towards the transverse central plane thereof.

References Cited by the Examiner UNITED STATES PATENTS 2,182,990 12/1939 Kishline 123-4132 2,767,694 10/1956 Boghossian 12341.82X

KARL J. ALBRECHT, Primary Examiner. 

1. AN INTERNAL COMBUSTION ENGINE CYLINDER HEAD HAVING THEREIN AN INLET MANIFOLD, INLET AND EXHAUST PASSAGES, AND PASSAGES FOR THE FLOW OF LIQUID COOLANT THERETHROUGH AND FORMED AS A TWO-PART CASTING, SAID HEAD BEING DIVIDED, SO AS TO FORM AN UPPER AND A LOWER CYLINDER HEAD PART, IN A PLANE WHICH INTERSECTS OPPOSITE SIDES OF THE HEAD AND IS SO SPACED FROM THE UPPER AND LOWER FACES OF THE CYLINDER HEAD THAT SAID EXHAUST PASSAGE LIE WHOLLY WITHIN THE 